Question

120/(x-y)+120/(x+y)=160/y 怎样化简成x＝2y和x＝-1/2y 急!急!在线等!

Answer 1

120/(x-y)+120/(x+y)=160/y

3/(x-y)+3/(x+y)=4/y

6x/(x^2-y^2)=4/y

4x^2-4y^2=6xy

2^2-3xy-2y^2=0

（2x+y)(x-2y)=0

所以

x＝2y或x＝-1/2y